title: Regional differences in tissue oxygenation during cardiopulmonary bypass for correction of congenital heart disease in neonates and small infants: relevance of near-infrared spectroscopy.
abstract: OBJECTIVE
  Cardiac surgery with cardiopulmonary bypass for correction of congenital heart disease in neonates and small infants is associated with considerable neurologic sequelae. We assessed the extent to which mixed venous oxygen saturation as a measure for adequacy of perfusion, reflects the oxygenation status of upper and lower body compartments. Moreover, we evaluated potential benefits of near-infrared spectroscopic monitoring of regional tissue oxygenation.
  
  
  METHODS
  Twenty patients (body weight < 10 kg) undergoing open cardiac procedures with cardiopulmonary bypass were enrolled. Blood samples were obtained in parallel from inferior and superior caval vein cannulas and mixed venous line and assessed for venous oxygen saturation and lactate levels. Data were compared to simultaneously measured tissue oxygenation indices obtained by near-infrared spectroscopy from brain and lower limb.
  
  
  RESULTS
  Venous oxygen saturation was lower and lactate concentration higher in blood from superior relative to inferior venous line. Mixed venous oxygen saturation correlated with venous oxygen saturation from inferior venous line and tissue oxygenation index of lower limb. No correlation was found between mixed venous oxygen saturation and venous oxygen saturation from superior venous line or cerebral tissue oxygenation index.
  
  
  CONCLUSIONS
  In neonates and small infants undergoing cardiac surgery with cardiopulmonary bypass, considerable regional differences exist in venous oxygen saturation. Mixed venous oxygen saturation primarily represents lower-torso oxygen status but poorly reflects and systematically overestimates upper-body oxygenation. Near-infrared spectroscopy yields additional information on regional oxygenation and may be valuable in early and sensitive detection of regional malperfusion in critical organs such as the brain.
authors.affiliation: Department of Anesthesia, Deutsches Herzzentrum Berlin, Berlin, Germany.
authors.forename: Mathias
authors.initials: M
authors.lastname: Redlin
authors.forename: Andreas
authors.initials: A
authors.lastname: Koster
authors.forename: Michael
authors.initials: M
authors.lastname: Huebler
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Boettcher
authors.forename: Nicole
authors.initials: N
authors.lastname: Nagdyman
authors.forename: Roland
authors.initials: R
authors.lastname: Hetzer
authors.forename: Hermann
authors.initials: H
authors.lastname: Kuppe
authors.forename: Wolfgang M
authors.initials: WM
authors.lastname: Kuebler
mesh_terms: D001784:Blood Gas Analysis; D001921:Brain / Q000098:blood supply; D006348:Cardiac Surgical Procedures / Q000379:methods / Q000401:mortality; D002315:Cardiopulmonary Bypass / Q000379:methods*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D035002:Lower Extremity / Q000098:blood supply; D008297:Male; D016343:Monitoring, Intraoperative / Q000379:methods; D010092:Oximetry; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology; D011183:Postoperative Complications / Q000401:mortality; D011336:Probability; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D019265:Spectroscopy, Near-Infrared; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D010100:Oxygen